Drill hole marker plug



June 1969 A. MATESAN DRILL HOLE MARKER PLUG Filed Nov. 15, 1966 m1VENTOR ANTE MATESAN United States Patent Olhce 3,451,370 DRILL HOLEMARKER PLUG Ante Matesan, 805 Regal Bldg, 144 W. Hastings St, Vancouver,British Columbia, Canada Filed Nov. 15, 1966, Ser. No. 594,558 Int. Cl.G01d 21/00 U.S. Cl. 116-114 6 Claims ABSTRACT OF THE DISCLOSURE A plughaving a hollow body with inner and outer end members. An open-endedtubular rod is telescopically mounted in the outer member and can beextended from the body to serve as a drill hole marker or can beretracted to a position substantially entirely within the body at whichtime the bore of the rod registers with an aperture in the inner endmember.

This invention relates to a device which serves as both a stopper and anindicator for a drill hole.

When a large number of holes are drilled prior to a blasting operation,it very often happens that a considerable time elapses before the holesare charged with the explosives. During this interval events may occurwhich will damage the holes or make them difiicult, or in someinstances, impossible to find. For example, heavy construction equipmentmoving over the drilled area can very soon make the holes useless fortheir intended purpose. A heavy rainfall will often erode the side wallsof the openings so that they are at least partially blocked. Shouldthere be a fall of snow, the holes are obliterated completely and thewhole project is held up until the snow disappears.

The use of plugs to protect such holes has been suggested before but thedevices hitherto used are such that they have not been widely acceptedby the construction and other industries. Conventional devices are oftenuneconomical and are otherwise unsatisfactory for a num ber of reasons.The plugs may be difficult to insert and remove from the holes. Often itwill be found that they do not clearly mark the holes. The plugs thenform half hidden obstructions which can be a nuisance and sometimes asource of danger to people or vehicles moved over the drilled ground.

The new and improved device of this invention overcomes the above andother disadvantages of the prior art. The present plug is readilyinserted 'by hand and normally is removed without the need for specialpulling equipment. Since the device is a press fit only, the holes arenot damaged by the plug insertion and removal. The device pinpoints thelocation of each hole and also makes it possible to discern the drillpattern at a glance.

The invention utilizes a hollow body which is inserted and lightlywedged in the exposed end of the drill hole. A long tubular rod issupported by the body to serve as a marker. One end of the rod can betelescoped into the body to facilitate threading of a fuse cord throughthe rod whereupon the rod can be raised to its full height so as to beeasily located from afar. The body has means for limiting itspenetration into the hole and other means to assist in subsequentremoval from the hole.

In the drawings,

FIGURE 1 is a vertical section of the invention, part broken away,

FIGURE 2 is a section taken on the line 22 of FIG- URE 1, and

FIGURE 3 is a section taken on the line 3-3 of FIG- URE l.

3,451,370 Patented June 24, 1969 Referring to the drawings, thepreferred embodiment of the device is shown to have a hollow andelongated body which is generally indicated by the numeral 10. The body10 has a cylindrical side wall 11 and an inner end Wall 12. The Wall 12is centrally apertured as at 14. Near the wall 12, the side wall 11 hasan inwardly tapered portion 16. A flange 18 is provided on the outersurface of the side wall 11, the flange being disposed in closeproximity to the externally threaded outer end 19 of said side wall.

Threadedly engaging the end 19 of the side wall is a cap 21 having acentrally disposed boss 22. An opening 23 is formed in the bossedportion of the cap 19 and preferably this opening is lined with a.sleeve 24- of a suitable bearing material. The peripheral edge of thecap is provided with a pair of diametrically opposed lugs 26 whichproject laterally therefrom.

A tubular rod 30 extends through the opening 23. This marker or locatingrod is preferably no more than several inches longer than the body 10,and has a bore 31 and an inner end 32. A stop washer 34 is welded orotherwise secured to the locating rod near the end 32. The rod 30 isslidably mounted in the cap 21 but it Will be noted the sleeve 24 offerssome resistance to the passage of the rod therethrough. Thus, thelocating rod can be raised or lowered with respect to the body 10 andwill be held in any selected position by the restraining action of thesleeve 24. When the rod 30 is telescoped or retracted into the body 10,the device is reduced to a length convenient for storage and handlingand when said rod is fully extended it is adequately supported by thecap 21.

The 'body 10 is provided with a protecting sleeve 36 formed of a thinplastic material. The sleeve is shaped to closely fit the side wall 11and, preferably, to cover at least part of the end wall 12 leaving theaperture 14- clear or unobstructed. 'Desirably, the length of theplastic sleeve is such that the outer end of said sleeve can be foldedoutwardly to extend beneath the flange 18-.

When an area of rock or the like is to be loosened by blasting, theground is drilled to provide a large number of suitably spaced holes 40,one of which is shown in FIGURE 1. A corresponding number of the markerplugs are collected at the site, the selected plugs having a bodydiameter closely conforming to the diameter of the holes being drilled.As each hole is drilled, or at least very shortly thereafter, it isfitted with one of the plugs. The plug is thrust into the upper end ofthe hole until the flange 18 abuts the surface 41 of the groundadjoining the hole. The rod 30 is then raised until the stop washer 34bears against the underside of the cap 21, thus providing maximumextension of the locating rod. The hole 40 is then sealed against looserock and other debris and is distinctly marked for future use.

If below freezing temperatures are likely to be encountered, a plasticsleeve 36 is fitted to each plug before the device is inserted into theground. The sleeve is slipped over the body 11 of the plug and the outerend of said sleeve is spread out so as to be clamped beneath the flange18 and the surface 41 of the ground. Should freezing occur, the plasticsleeve 36 prevents the metal plug from sticking to the sides of thehole. The plug can then 'be removed simply by pulling upwardly on thelugs 26.

When the time comes to load the drill holes with explosives there may bea delay before all the holes are suitably charged and connected up forsimultaneous firing. Again, the plugs are useful to seal and mark thecharged holes. To load a hole with an explosive charge, the plug isremoved and the charge is lowered into the hole by means of thedetonating cord 43 which may be a fuse or insulated wire. Assuming thecharge is to be fired electrically, the insulated wire 43 attached tothe charge is threaded through the rod 30. This is done by first movingthe locating rod into the body 10 until its end 32 abuts the wall 12.The bore 31 of the rod now communicates directly with the opening 14 inthe inner end wall. The wire then can be fed through the marker plugwithout difiiculty and a length of the wire can be left protruding fromthe outer end of the rod 30 for connection to the firing circuit. Thelocating rod is pulled outwardly to its fully extended position and theplug is reinserted in the hole.

By using the plug in this manner, the hole is tamped and both theexplosive charge and the hole are protected. Also a clear warning isgiven that the area is charged and ready for firing. When firing takesplace, the marker plugs obviously are lost or damaged but because oftheir inexpensive construction this is not too important.

The use of the plastic sleeve 36 is particularly important when groundtemperatures are likely to be even close to freezing since a metal body10 has been found to have a strong tendency to stick to the side wallsof the hole. A sleeve 36 is fitted to the plug whenever the temperatureis low or likely to become low at any time when thedevice is in use.Alternatively, the body 10 can be made of some suitable plastic materialwhich obviates the need for using the sleeve 36 under the abovementionedcircumstances.

What I claim as my invention is:

1. A marker plug for a drill hole, said plug comprising an elongatedbody adapted to be inserted into the upper end of the drill hole, saidelongated body being hollow and having a cylindrical side wall, an innerend member and an outer end member, a locating rod having a boretherethrough telescopically mounted in the elongated body in axialalignment therewith, said outer end member having an opening throughwhich the locating rod extends, said inner end member having an apertureregistering with the bore of the locating rod, said locating rodnormally retracted into the elongated body and providing access to saiddrill hole and being extendable therefrom to mark the location of saiddrill hole.

2. A marker plug as claimed in claim 1, said cylindrical side wallhaving a tapered portion adjacent the inner end member.

3, A marker plug as claimed in claim 1, said locating rod beingfrictionally supported in the opening of the outer end member and meanson said rod for limiting movement of the locating rod outwardly of theelongated body.

4. A marker plug as claimed in claim 1, said cylindrical side Wallhaving an external flange adjacent the outer end member, said externalflange being adapted to halt movement of the elongated body inwardly ofthe drill hole.

5. A marker plug as claimed in claim 4, having a pair of lugs projectinglaterally from said cylindrical side wall, said pair of lugs beingspaced outwardly of the external flange.

6. A marker plug as claimed in claim 1, having a flexible sleeveenclosing the cylindrical side wall, said flexible sleeve having a rimportion contacted by the external flange.

References Cited UNITED STATES PATENTS 1,822,141 9/1931 Gallaher l6696XR 2,345,219 3/1944 Sanderson 16669 XR 2,562,946 8/1951 Read l66753,166,041 1/1965 Caggainello 116-1 14 3,189,099 6/1965 O'tteman et a1.l6675 XR 3,204,355 9/1965 Whitman 40-40 LOUIS J. CAPOZI, PrimaryExaminer.

US. Cl. X.R, l66179

